Plant Optimization And Allocation In Ecological Control Measures Of Agricultural Land Retreat In Harbin

The most important part of all the measures taken for the ecological management of water withdrawal in farmland is the plant measures.Meanwhile,the farmland ecosystem is also affected by the plant measures and the ecological function is limited.In this paper,based on the treatment effect of plants on nitrogen,phosphorus and other major farmland pollutants,and combining with the agriculture and climate characteristics of zhuhai,the plants suitable for the ecological treatment of farmland drainage in zhuhai were selected and optimized.Based on the investigation and the existing research results of this unit,five species of plants were selected as the research object,including qianqu,irisail,rechargeable flower,canna,floret and asparagus,for special research on growth characteristics,adaptability and purification capacity,and the optimization of planting scheme was conducted according to the research results.Based on the fuzzy evaluation principle,four technologies,namely pesticide reduction and residue control technology,fertilizer reduction technology,soil tillage optimization technology and planting system optimization technology,are suitable for the non-point source pollution source control technology adopted in our city.Buffer zone technology,land and water intersection zone technology and ecological ditch technology are three kinds of non-point source pollution process blocking technology suitable for our city.Artificial wetland technology and detention and interception technology are suitable for the treatment of non-point source pollution at the end of the city.In the study on the growth characteristics of aquatic plants,the survival rate of these five plants was successively from low to high,that is,leaf asparagus(48.9%),rechargeable flower(91.6%),canna(92.2%),iris(93.2%),and kundera(96.7%).The seedling retardation time was used as the index for the study.From high to low,it was successively divided into fescue,iris germanica,canna,rehmannia and lysiflora.The florescence of the three species of plants--rechargea,canna,and irises--was delayed by about one month compared with those in other cold regions,while the other two plants did not blossom.By using the wilting period as the index to study,it can be concluded that the earliest wilting period is lythrum and rechargeable flower,while the wilting period of unflowering German iris and geranium is far less than the other three.In the measured growth period with a duration of 152 days,the growth rate of the root systems of 5 plants was successively from low to high,which was qianqu(109.7%),canna(166.3%),irises(213.1%),rechargeable flowers(309.3%)and asparagus edulis(381.1%).In the study on the adaptability of aquatic plants,among the five plants,the seedling with the strongest cold resistance ability is lythrum,the flowering period is the longest is canna,and the seedling with the strongest cold resistance ability is iris germanica.The order of submergence performance was: irisa > reinforcea > canna >Willow food >Mosaic bamboo reed,and drought-resistance performance was: irisa > reinforcea> Willow food > canna > Mosaic bamboo reed.In the research of aquatic plant purification effect on COD removal effect is the best to spend,on TP removal effect is the best kind vegetables,on PO43--P removal effect is the best kind food,best on TN removal effect is canna,various aquatic plants to NO3--N removal effects are obviously,after the experiment,all the nitrate concentrations were reduced in the experimental group to set value(below instrument can determine the minimum concentration).Taking the growth characteristics,adaptability,purification effect and landscape of aquatic plants into consideration,9 indexes of 4 categories were selected to comprehensively evaluate the selected aquatic plants suitable for planting in Harbin.In combination with the evaluation results of each plant,the three schemes set in the experiment were comprehensively optimized and scored.The optimized results enhance the landscape to a certain extent.All the selected plants have strong adaptability and purification functions,which can play a positive role in improving the water quality.The configuration of aquatic plants in the related design of farmland drainage channels in Harbin can be configured by referring to plan 2 in this study.